Replacing the Fullerene in Plastic Solar Cells

March 17, 2014

Repurposing Automotive Paint for Solar
Cells

A team of UC
Santa Barbara researchers led by Institute faculty Thuc-Quyen Nguyen and
Guillermo Bazan has developed a new type of plastic solar cell utilizing a
molecule extremely similar to the dye used in red automotive paint. The vast
majority of plastic solar cells are made by combining a special type of plastic
with a fullerene molecule. Fullerene molecules are spherical nanostructured
forms of carbon that are produced in small batches using relatively large
amounts of energy and harsh chemicals. The research team at UC Santa Barbara was
able to successfully replace the fullerene with a molecule very similar to dyes
that are currently produced economically by the thousands of tons.

Path to Commercialization

Figure 2: Chemical structure of the dye molecule used by the UC Santa Barbara research team to replace fullerene molecules.

Due to the ease
with which these dye molecules are produced in large quantities, successfully incorporating
them into plastic solar cells could expedite commercialization of this
technology. Additionally, these dye molecules absorb more light than fullerenes
— clearly a benefit for solar cells, which work by converting light from the
sun into electricity. Solar cells using this dye molecule, however, aren’t
quite as efficient as solar cells using fullerene molecules. Plastic solar
cells using fullerene molecules convert almost every absorbed photon into
electrical current, whereas solar cells using the dye molecule studied in this
work only convert about half the absorbed photons into electricity. This is
still significantly better than many of the other molecules that have been
tried as fullerene replacements, and is notably one of the highest performing non-fullerene
plastic solar cells. The research team is still working to understand specifically
why these dye molecules don’t perform as well as fullerenes so that they can be
leveraged to produce efficient plastic solar cells on an industrial scale. Use
of such materials makes plastic solar cells more likely to play a significant
role in lessening society’s dependence on fossil fuels.